Armrest

ABSTRACT

The invention relates to an armrest, such as a middle armrest, comprising an armrest body ( 17 ) which may be pivoted about a horizontal axis ( 12 ), between an upright and a lowered position, provided with a ratchet lock (P, S), only operating on a downwards pivoting movement (N), which comprises a primary section (P), arranged to rotate about the axis ( 12 ) in connection with the armrest body ( 17 ), with a secondary piece (S), mounted such as to be stationary, at least relative to the axis ( 12 ), cooperating therewith. The ratchet lock (P, S) separates the primary piece (P) and the secondary piece (S) from each other in the upright position and on beginning an upwards pivoting movement (N), by means of a control device (R) and returns the above to engagement in a lowered position. The primary piece (P) and the secondary piece (S) form facing planes of ratchet teeth (Z 1,  Z 2 ), which are coaxial to the axis ( 12 ). The secondary piece (S) may be axially displaced. The control device (R), which takes the primary piece (P) and secondary piece (S) out of engagement, comprises a peripheral cam ( 42 ), enclosing the primary piece (P) and a control track fixed to the secondary piece (S).

The invention relates to an arm rest, for instance a center arm rest,corresponding to the introductory clause of claim 1. Such an arm restfor a motor vehicle is described in EP 1,164,051.

The arm rest according to EP 1,164,051 has primary and secondary partswith surfaces centered on a common axis (center axis), confronting eachother, and formed like a jaw clutch with face teeth, the primary partmounted on the arm-rest body being pivotal and also axially movable.

The latch teeth of EP 1,164,151 having blocking and sliding flanks likeHirth teeth or a jaw clutch make it possible with fairly small primaryand secondary parts to withstand substantial angular load moments. Inaddition this known arm rest makes it possible for a control device todetermine at what angular positions the primary and secondary parts meshso that downward pivoting of the arm-rest body is blocked in theselected positions.

The control device for this arm rest is two cam bumps on the primarypart. More particularly a control ring between the primary part andsecondary part is rotationally coupled to the primary part and carriesin the two radially projecting cam bumps in diametrally oppositelocations. The control ring is formed as a separate part can, accordingto requirements, be better designed, e.g. by being formed integrallywith the primary part.

To resist greater torque loads, EP 1,164,051 optimizes the face teeth ofthe primary part and secondary part in that the teeth of the primarypart and of the secondary part are each formed as annularly continuousrings which can therefore be made so big that the outer periphery of thecircular area corresponds to the outer periphery of the cross sectionsof the primary part and/or secondary part with the teeth extendingaround the entire circumference of the primary part and secondary part.In order to block downward movement of the arm-rest arm, all the teeth,that is a multiplicity of teeth, mesh.

The dependence of the control ring on the pivotal movement of thearm-rest body in the known arrangement is eliminated over a small anglein that the primary part has two circular-segmental slots open in itsplane toward the secondary part in each of which a cam bump projectingfrom the control ring toward the primary part engages and whichcooperate with a stationary cam track of the secondary element. In thismanner each cam bump of the control ring is of a smaller angulardimension than the respective slot of the primary part. As a result ofthe different angular dimensions of the slots (large) and cam bump(small) the primary part both in the lowered position and at the startof upward pivoting as well as in the raised position and at the start ofdownward pivoting of the arm-rest body has some play before engagementof the cam bumps with the first or second end faces of the respectiveslots.

In EP 1,165,051 a compression spring coaxial with the secondary part andprimary part presses the primary part fixed on the arm-rest body axiallyagainst the secondary part. The axial shiftability of the primary partis limited by a plate-shaped abutment fixed on the common central axle.Thus the compression spring is effective via a particularpressure-distributing plate on the tooth-free outer end of the primarypart which creates a relatively bulky and expensive construction.

In the arm rest according to EP 1,164,501 there is also the disadvantagethat with a small upward adjustment of the arm-rest body which iscoupled to the axially movable primary part creates a small axialmovement of the arm-rest body which can be a problem in close quarters.

In order to prevent damage to such an arm rest the maximum load shouldnot exceed for example 80 daN. It is even preferable to provide a marginof safety and to set up the arm rest with an overload protector thatresponds at about 30 daN, that for example decouples the toothedstructure so that when the load limit is exceeded the arm-rest body canbe deflected downward to a position determined by a vehicle-bodyabutment. Such an overload protector is generally described for examplein German 2,714,581.

It is an object of the invention to, starting with the above-describedarm rest according to EP 1,164,051, so to improve on the known arm restthat it can withstand a greater load, takes up less space, and has alonger service life.

This object is achieved according to the features of the introductoryclause of claim 1 in combination with those of the characterizingclause.

According to the invention the primary part is axially fixed on theaxle. Fixing the primary part on the arm-rest body ensures that thearm-rest body when pivoted upwardly will not move axially so that thearm rest according to the invention can be used comfortably even inrelatively close quarters.

Also according to the invention the abutment is provided to the end ofthe secondary part opposite its teeth and at least one compressionspring is provided between the secondary part and the abutment. In thismanner, namely by bracing the spring directly between the axiallymovable secondary part and the axially fixed primary part, the inventionavoids the bulky and expensive construction of EP 1,1264,501 whichrequires a pressure-distributing plate not needed by the invention.

In addition the control ring can be mounted in a particularly compactmanner in the space between the primary part and the secondary part ingenerally cylindrical recesses that are open toward each other and thattogether hold the control ring.

Finally the invention proposes that an overload protector is formed as aspring-loaded abutment bearing on the secondary part so that downwardpivoting from the lowered position is possible.

In particular a pusher is rotationally fixed but axially shiftable onthe axle on a side of the abutment turned away from the secondary partand is biased by a spring force against the abutment. Furthermorecoupling-claw projections of the abutment and of the pusher have axiallyand radially extending flanks that bear on each other on upward pivotingand slide flanks that extend at an angle to the axle and that bear oneach other on downward pivoting.

In this case a force of about for example 30 daN is exerted downward onthe arm-rest body and is converted into a torque effective through theprimary and secondary parts to the fixed abutment on the axle, theangled slide flanks of the coupling-claw projections of the abutmentpressing angularly against the angled slide flanks of the coupling-clawprojections of the pusher. The result is that the pusher, which isaxially shiftable but rotationally fixed on the axle, can move againstthe force of for example a spring-washer pack away from the abutment.

This works such that the coupling-claw projections of the abutment canmove with their angled slide flanks over the coupling-claw projectionsand shift the pusher axially while the secondary part can in this mannermove out of the way.

According to a further embodiment of the invention the axle is splinedalong its entire length, the primary part, the control ring, thesecondary part, and the abutment each having a smooth central borethrough which the axle extends and which allows free rotation, thepusher at least having a central bore complementary to and rotationallycoupling it to the axle.

In order to avoid the central axle being a relatively expensive part,according to the invention a shaft is used having full-length splines.Such a splined shaft are standard items sold by length. Such a splinedshaft has the advantage that the primary part, the control ring, thesecondary part, and the abutment can each be mounted rotatably by asmooth central throughgoing bore on the splined shaft. In case on thecontrary something needs to be angularly coupled to the axle, as forexample a pusher described more fully below, this part can be providedwith a central throughgoing bore complementary to the splined shaft.

The spline shaft also makes it possible for something to slide ifnecessary axially along the axle, both the elements carried thereon withsmooth throughgoing bores and a part with a complementarily shaped bore,e.g. the pusher. In case one of these elements, be it one with a smoothcentral throughgoing bore or one with a splined central bore, needs tobe axially fixed on the shaft, according the invention the axle isprovided with at least one recess on its outer surface, as e.g. anannular groove for holding an annular retaining element, e.g. a snapring.

A further substantial advantage of the present invention is the resultof the features according to which in the lifting direction each cambump after leaving the respective cam recess and riding onto therespective flat cam track engages a ridge formed as a control bumpprojecting axially toward the control ring and against which the cambump engages on downward pivoting.

The control bump ensures that on downward pivoting of the arm rest whichentails downward pivoting of the primary part fixed to the arm rest, thecam bump of the control ring comes up against the control bump and ismomentarily stopped. This ensures that the cam bump of the primary partrotates inside the cam recess relative to the control ring so that itcan travel through the play of e.g. 15° necessary for later adjustment.

It is particularly advantages according to this last-described featurewhen further according to the invention the control bump is immediatelyadjacent the respective control recess. This means that the cam bump ofthe control ring after substantial lifting of the arm rest through morethan 15° must only get over the control bump so that on a subsequentdownward movement the play of about 15° is taken up.

Additional features of the invention are given in the dependent claims.

The drawing shows preferred embodiments, that is a first embodiment(FIGS. 1-10C) and a second embodiment (FIGS. 11-17A), therein:

FIG. 1 is a three-dimensional representation of the mechanical elementsof an arm rest;

FIG. 2 shows the elements of FIG. 1 without the outer tube shielding theinner parts;

FIGS. 3 and 4 are exploded views of the structure of FIG. 2 with aschematically illustrated arm support seen from two different angles;

FIG. 5 is a view like FIG. 3 but seen at an 180° opposite angle;

FIG. 6 is a side view of the primary part of FIGS. 2 and 3;

FIG. 6A is an end view taken in the direction of arrow VIA of FIG. 6;

FIG. 6 b is a sectional view taken along plane VIB-VIB of FIG. 6A;

FIG. 7 is an end view of a control ring;

FIG. 7A is a radial cross section taken along line VIIA-VIIA of FIG. 7,with FIG. 7A corresponding to the FIG. 3 embodiment;

FIG. 7B is a side view of control ring in a position offset to that ofFIG. 7A by 180°;

FIG. 7C is an end view taken in the direction of arrow VIIC of FIG. 7B;

FIG. 8 is a side view of a secondary part of the embodiment of FIG. 3;

FIG. 8A is an end view taken in the direction of arrow VIIIA of FIG. 8;

FIG. 8B is an axial section taken along line VIIIB-VIIIB of FIG. 8A;

FIG. 8C is a section offset by 90° from that of FIG. 8 b and taken alongline VIIIC-VIIIC of FIG. 8A;

FIG. 8D is an end view taken in the direction of arrow VIIID of FIG. 8;

FIG. 9 is a side view of an abutment part according to the embodiment ofFIG. 3;

FIG. 9A is an end view taken in the direction of arrow IXA of FIG. 9;

FIG. 9B is an end view taken in the direction of arrow IXB of FIG. 9;

FIG. 9C is an axial section taken along line IXC-IXC of FIG. 9B;

FIG. 9D is an axial section offset by 90° from that of FIG. 9C and takenalong line IXD-IXD of FIG. 9B;

FIG. 10 is an end view of a pusher part, taken in the direction of arrowX of FIG. 10B;

FIG. 10A is an axial section taken along line XA-XA of FIG. 10;

FIG. 10B is a side view taken in the direction of arrow XB of FIG. 10;

FIG. 10C is an end view taken in the direction of arrow XC of FIG. 10B;

FIG. 11 is a perspective view of the elements of an alternate arm rest;

FIG. 12 is a view like FIG. 11 of the elements but with out the outertube shielding the inner parts;

FIG. 13 is an exploded view with a schematically illustrated arm-restsupport;

FIG. 14 is a side view of the primary part of the embodiment of FIGS. 12and 13;

FIG. 14A is an end view of the primary part taken in the direction ofarrow XIVA of FIG. 14;

FIG. 14B is an axial section taken along line XIVB-XIVB of FIG. 14A;

FIG. 15 is an end view of the control ring;

FIG. 15A is an axial section taken along line XVA-XVA of FIG. 15, FIG.15A corresponding to the embodiment of FIGS. 12 and 13;

FIG. 15B is a side view of the control ring in a position offset by 180°to that of FIG. 15A;

FIG. 15C is an end view taken in the direction of arrow XVC of FIG. 15B;

FIG. 16 is a side view of the secondary part of the embodiment of FIGS.12 and 13;

FIG. 16A is an end view taken in the direction of arrow XVIA of FIG. 16;

FIG. 16B is an axial section taken along line XVIB-XVIB of FIG. 16A;

FIG. 16C is an axial section in a position offset by 90° to that of FIG.16B and taken along section line XVIC-XVIC of FIG. 16A;

FIG. 16D is an end view taken in the direction of arrow XVID of FIG. 16;

FIG. 17 is an end view taken in the direction of arrow XVII of FIG. 17A;and

FIG. 17A is an axial section taken along line XVIIA-XVIIA of FIG. 17.

In the following drawing description, in spite of structuraldifferences, the same reference numerals are applied to analogouselements in both the embodiment of FIGS. 1-10C and the embodiment ofFIGS. 11-17A

The arm rest is shown in general (see FIGS. 3 and 13) at 10.

The support element of the mechanism 11 of the arm rest 10 is astationary axle 12 fixed by mounts 13 to an unillustrated vehicle body.The axle 12 has in the embodiment of FIGS. 11-17A a corrugated profile,that is external splines.

Much of the mechanism 11 is surrounded by an outer shield tube 14 havingat each end a shoulder 15 bearing on a straight inner end portion 16 ofa respective arcuate arm-rest support arm 17 or 18. In this manner thesupport arm 17 shown in FIGS. 1-4 and FIGS. 11 and 13 on the right andin FIG. 5 on the left is rotationally fixed to the support arm 18 shownon the left in FIGS. 1-4 and FIGS. 11 and 13 and in FIG. 5 on the right.

Two generally U-shaped hollow arms 19 extend from an arm-rest support 20and are connected in an unillustrated manner with the two support arms17 and 18.

Since forces F against the arm-rest support 20 are mainly transmitted bythe arm 17 into the mechanism 11, the arm 17 in the following isreferred to generally as the “arm-rest body” or “pivotal arm-rest body.”

As shown in particular in FIG. 3, a hexagonal socket 21 of the supportarm 17 fits over a hexagonal nut 22 formed integrally with a primarypart P. As shown in FIGS. 11 and 13, instead of a hexagonal socket thereis a Torx socket 21 and instead of the hexagonal nut there is a Torxformation 22 on the primary part P. Each end of the axle 12 carries anonrotatable end part 58. The support arm 18 is rotationally supportedby a sleeve 59 on the axle 12.

The primary part P as well as a control ring R, a secondary part S, anabutment W, a pusher D, a spring-washer pack T, and a setting nut E aremounted coaxially on the axle 12. The setting nut E or an equivalentpart is not shown in FIGS. 11-13.

In order to axially fix the support arm 17, a snap ring 23 engages in anannular groove 24 of the axle 12.

The primary part is shown in more detail in FIGS. 6-6B and 14-14B. Theprimary part P illustrated in FIGS. 6 and 14 corresponds to theembodiment of FIG. 3 and FIGS. 12 and 13, respectively. The primary partP has face teeth Z1 shaped like the Hirth teeth of a jaw clutch, so thatthe teeth each have a shallow slide flank facing in one direction and asteep or undercut blocking flank facing in the opposite direction. Theteeth Z1 are arrayed in a continuous ring whose outer periphery isvirtually level with the outer periphery of the primary part P so thatthe teeth Z1 have as a result of this formation considerableload-bearing capacity and thus are able to withstand relatively largeangular loads.

The secondary part S has face teeth Z2 just like the teeth Z1 of theprimary part P.

FIGS. 8 and 16 show the secondary part in the embodiment of FIGS. 3 andof FIGS. 12 and 13, respectively. The face teeth Z2 of the secondarypart S are oriented relative to the face teeth Z1 of the primary part Psuch that when the support arm 17 swings upward as shown by arrow A (seeFIGS. 3 and 13) the blocking flanks of the face teeth Z1 of the primarypart P slide over the slide flanks of the face teeth Z2 of the secondarypart S which normally is nonrotatable on the axle 12.

In case however the blocking flanks of the face teeth Z1 and Z2 bearangularly on each other and the force F (see FIGS. 3 and 13) is exerteddownward on the arm support 20, downward-swing torque in the directionof arrow N is exerted on the face teeth Z1 of the primary part P. Theresult is that the blocking flanks of the nonrotatable secondary part Slock and downward pivoting is impossible in the rotation direction N.

As mentioned, the secondary part S normally cannot rotate on the axle12, but is rotatably mounted with its smooth central hole 26 on the axle12 like the primary part P with its smooth central bore 25. In case ofan overload, the situation is different for the secondary part S as willbe described in the following.

In the embodiment of FIGS. 3 and 13 the end face turned toward theprimary part P of the secondary part S is juxtaposed with the abutment Wthat fits with a smooth central bore 27 over the axle 12 and is axiallysecured by a snap ring 28 (axial retaining ring) fitting in anotherradially outwardly open groove 24 on the axle 12.

The secondary part S and the abutment W are formed on their confrontingend faces with respective axially projecting coupling claws 29 and 30that serve to rotationally couple the axially shiftable secondary part Sand the abutment W axially fixed on the axle 12.

Each coupling claw 29 and 30 and each recess 31 formed between adjacentcoupling claws 29 of the secondary part S and claws 30 of the abutment Wis formed with an axially open blind hole 33 in which can fit arespective one of four coil compression springs 34 extending parallel tothe axle 12.

Instead of the four compression springs 34 a single coaxial compressionspring (see 34 in FIG. 13) can be provided between the secondary part Sand the abutment W, bearing on unillustrated annular shoulders of therespective outer surfaces of the secondary apart S and the abutment W.

The end face of the abutment W turned away from the secondary part S isjuxtaposed with the pusher D. The pusher D (see FIGS. 10-10C) has aninternal polygonal bore 35 that can slide but not rotate on acomplementary square region 53 of the axle 12. In the embodiment ofFIGS. 11-17A the pusher D (see FIGS. 17 and 17A) has instead of thepolygonal bore a central hole 35 that is splined like the axle 12 sothat the pusher D cannot rotate but can slide on the axle 12.

The abutment W and the pusher D have respective interengageable couplingprojections 36 and 37 on their confronting end faces. The coupling-clawprojections 36 of the abutment W have axially and radially extendingfaces 38 that bear on axially and radially extending faces 39 of the twocoupling-claw projections 37 of the pusher D.

In addition the two coupling-claw projections 36 of the abutment W bearwith faces 40 angled to the axle 12 on complementarily angled faces 41of the two coupling-claw projections 37 of the pusher D.

The washer-spring pack T is provided at the end face of the pusher Dturned away from the abutment W. The spring pack biases the pusher Dwith a spring force against the abutment W which cannot move axially onthe axle 12. The setting nut E (which is the same in FIGS. 12 and 13 butnot shown) is carried on an external screwthread of the axle 12 so thatthe prestressing of the spring pack T can be set and adjusted.

The control ring R mounted between the primary part P and the secondarypart S and having a smooth central bore 54 through which passes the axle12 fulfills a particular function, is rotationally coupled with theprimary part P, and has on its end face turned toward the secondary parttwo control cam bumps 42 (see FIGS. 7-7C; FIGS. 15-15C) that coact withcam tracks 43 of the secondary part S.

The primary part P (see FIGS. 6-7B and FIGS. 14-14B) has a coupling bump44 projecting toward the secondary part S and engaging in a couplingrecess 45 open on the control ring R toward the primary part P.

The primary part P and the secondary part S have the end teeth Z1 and Z2arrayed in circular rings. The outer periphery of each ring generallycorresponds to the outer periphery of the body of the respective primarypart P or secondary part.

Each set of face teeth Z1 and Z2 extends around the entire periphery ofthe respective primary part P or secondary part S.

The primary part P and the secondary part S are formed radially inwardof the respective teeth Z1 and Z2 with generally cylindrical recesses 46and 47. The cylindrical recesses 46 and 47 are open toward each otherand thus form a cavity in which the control ring R is received. Forcertain applications it can be advantageous to provide more frictionbetween the recess 46 of the primary part P and the correspondingsurface of the control ring R than between the recess 47 of thesecondary part and the other corresponding surface of the control ringR. To this end the recess 46 of the primary part P is formed with acircular V-shaped groove 56 and the control ring R with a complementaryV-shaped ridge 60.

The coupling recess 45 of the control ring R extends over a greaterangle β than the angle α of the coupling bump 44 of the primary part P.For example the angle β=60° and the angle α=45° so that the couplingbump 44 has about 15° of play.

The two cam bumps 42 of the control ring R are engageable in respectivecam recesses 48 of the cam tracks 43 of the secondary part S. The camtracks 43 form annular surfaces centered on the axle 12 at the base ofthe cylindrical recess 47 of the control ring R.

The arm rest shown in the drawing functions as follows:

When the arm-rest support 17 is in its lowermost position, the couplingbump 44 bears on a second abutment face 50 of the coupling recess 45 ofthe control ring R. Since the angle β of the coupling recess 45 is forexample 15° larger than the angle α of the coupling bump 44, the primarypart P fixed rotationally to the arm-rest body 17 has about 15° of play.The arm-rest body can ratchet over for example four teeth of therotationally fixed face teeth Z2 of the secondary part while movingthrough this play.

Immediate downward movement out of one of these four positions is notpossible, because the teeth Z1 and Z2 are locked together.

A limited upward pivoting of 15° is nonetheless possible, because theblocking flanks of the teeth Z1 of the primary part P can slipunhindered over the slide flanks over the nonrotatable teeth Z2 of thesecondary part S.

In this manner it is possible to shift the arm-rest body 17 upward intoan upright position, but the ratcheting sound made by the teeth Z1 andZ2 is somewhat bothersome. In order to eliminate this noise, theinvention works as follows:

As soon as the coupling bump 44 comes into contact against a firstabutment face 49 of the coupling recess 45 of the control ring R and theupward movement continues in rotation direction A, the two cam bumps 42engage with angled faces 51 on angled faces 52 of the secondary-part camrecesses 48 and rise therefrom as indicated at A in FIGS. 7, 7C, and 8Dand in FIGS. 15, 15C, and 16D.

In this manner the secondary part S is shifted back away from theprimary part P against the force of the springs 34 so that the teeth Z1and Z2 disengage from each other and the support arm 17 can be swungsilently into its upright position. During this upward movement the twocam bumps 42 slide on the flat cam tracks 43.

If now, starting from the upright position of the arm-rest body 17, adownward pivoting is initiated, the coupling bump 44 moves in theangular direction N from the first abutment face 49 back into theabove-described starting position against the abutment face 50.

Thus the cam bumps 42 move again over the flat cam tracks 43 backward inangular direction N (see FIGS. 7C and 8D as well as FIGS. 15C and 16D)and finally slide back again into the cam recesses 48 of thesecondary-part cam tracks 43, whereupon the arm-rest body 17 findsitself again in its above-described lowermost starting position and theface teeth Z1 and Z2 are again in mesh with each other.

In order to insure that in every case when downwardly pivoting in theangular direction N the coupling bump 44 moves from the first abutmentface back into the above-described position on the abutment face 15 sothat a subsequent adjustment upward in direction A ensures a shift of15°, the invention provides the following as shown in the embodiment ofFIGS. 11-17A:

Control bumps 55 project from the flat cam tracks 43 in an axialdirection x toward the control ring R immediately adjacent in the upwardrotation direction A from each secondary-part cam recess 48.

As soon as the coupling bump 44 engages against the first abutment face49 of the cam recess 45 of the control ring R and upward pivotingcontinues in angular direction A, the two cam bumps 42 slide with theirangled flanks 51 over the angled flanks 52 of the secondary-part camrecesses 48 and rise out of them and then, as shown in FIG. 16D, comeinto engagement with the control bumps 55 and slide over them. Thispushes the secondary part S against the spring force, that is againstthe force of the single coil spring 34, away from the primary part P sothat the face teeth Z1 and Z2 disengage from each other and the supportarm 17 can move silently into its upright position. During this upwardpivoting in the direction A the two cam bumps 42 slide over the flat camtracks 43. When however, starting in the completely raised position ofthe support arm 17, which is defined by an external abutment, downwardpivoting in the direction N is initiated, the coupling bump 44 moves inthe direction N from the first abutment face 49 back into itsabove-described starting position against the abutment face 50. In orderthat this reverse rotation can take place, there must be some relativemovement between the primary part P and the control ring R, which ismade possible by friction in the embodiment of FIGS. 1-10C so as to holdback the control ring R relative to the secondary-part cam tracks 43.This holding back is done however according to FIG. 16D by the controlbump 55 because the cam bump 42, when moving downward in the directionN, moves against a face 57 of the control bump 55 and thus ensuresengagement of the primary-part coupling bump 44 against the secondabutment face 50 of the control ring R.

For the situation when the arm-rest body 17 is in its lowermost positionand an overload is applied in direction F to the arm-rest body 17 so asto press the arm-rest body 17 downward in pivot direction N, the teethZ1 and Z2 are locked together.

The rotary coupling by means of the coupling claws 29 and 30 of thesecondary part S and the abutment W transmits overload torque to theabutment so that the abutment W rotates in direction N (see FIGS. 2 and12) and the angled slide faces 40 of the coupling-claw projections 36 ofthe abutment W act on the angled slide faces 41 of the coupling-clawprojections 37 of the pusher D in axial direction x. In this manner incase of an overload in rotation direction N, the abutment W can rotaterelative to the pusher D and deflect so as to unload the arm rest 10.

1-23. (canceled)
 24. a vehicular arm rest comprising: a fixed axleextending along an axis; a primary part rotatably about the axis on theaxle, axially fixed on the axle, and formed with an array of axiallydirected teeth; an arm-rest body fixed to the primary part and pivotabletherewith about the axis between a raised position and a loweredposition; a secondary part at most limitedly pivotal about the axis onthe axle, axially shiftable on the axle, and having an array of axiallydirected teeth meshable with the primary-part teeth, the teeth of bothparts being angled such that when meshed they inhibit movement of thearm-rest body from the raised to the lowered position but permitmovement of the arm-rest body from the lowered to the raised position;an abutment axially fixed on the axle with the secondary part betweenthe abutment and the primary part; spring means braced axially betweenthe abutment and the secondary part for urging the secondary-part teethinto mesh with the primary-part teeth; and control means between theprimary part and the secondary part and including cam formations forpushing the secondary part away from the primary part on pivoting of theprimary part from the raised position of the arm-rest body toward thelowered position for decoupling the primary-part teeth from thesecondary-part teeth and for coupling the primary-part teeth with thesecondary-part teeth on pivoting into the lowered position.
 25. Thevehicular arm rest defined in claim 24 wherein the control meansincludes: a control ring between the primary part and the secondary partand having a cam side turned toward one of the parts and a coupling sideturned toward the other of the parts, the one part having a cam sideturned toward the control-ring cam side and the other part having acoupling side turned toward the control-ring coupling side, the camformations being on the cam sides; a coupling bump on one of thecoupling sides and projecting toward the other coupling side; and acoupling recess on the other of the coupling sides open toward the onecoupling side and receiving the cam bump.
 26. The vehicular arm restdefined in claim 25 wherein 25 wherein each of the arrays of teeth issubstantially circular and both of the parts are formed radially inwardof the respective arrays with generally cylindrical recesses open towardeach other and forming a cavity holding the control ring.
 27. Thevehicular arm rest defined in claim 26 wherein the coupling bump has apredetermined angular dimension and the coupling recess has apredetermined angular dimension greater than that of the coupling bump,whereby the coupling bump can move angularly within the coupling recesspermitting limited relative angular movement between the control ringand the other part.
 28. The vehicular arm rest defined in claim 25wherein the cam formations include: an annular cam track on one of thecam faces; a cam recess in the track on the one face and open toward theother cam face; a cam bump formed on the other cam face, projectingaxially toward the other of the cam faces, and riding on the cam track,the cam bump, cam track, and cam recess being constructed such that whenthe cam bump is riding on the cam track the primary-part teeth are heldout of mesh with the secondary-part teeth and when the cam bump isengaged in the cam recess the primary-part teeth mesh with thesecondary-part teeth.
 29. The vehicular arm rest defined in claim 28wherein the track is generally circular, planar and perpendicular to theaxis.
 30. The vehicular arm rest defined in claim 28 wherein the controlmeans shifts the cam bump out of the cam recess on pivoting toward theraised position, also shifts the cam bump out of the cam recess onpivoting out of the raised position toward the lowered position, butpositions the cam bump in the recess on pivoting toward the loweredposition from any position between the raised and lowered positions. 31.The vehicular arm rest defined in claim 28 wherein the track is formedoffset from the recess with a ridge, the cam bump riding over the ridgeon displacement of the arm-rest body from the raised to the loweredposition.
 32. The vehicular arm rest defined in claim 31 wherein theridge is immediately adjacent the cam recess.
 33. The vehicular arm restdefined in claim 24, further comprising formations rotationally couplingthe abutment to the secondary part.
 34. The vehicular arm rest definedin claim 33 wherein the formations coupling the abutment to thesecondary part include a plurality of axially extending coupling teethon the abutment and on the secondary part having faces extendingparallel to the axis and bearing angularly on each other.
 35. Thevehicular arm rest defined in claim 34 wherein the abutment andsecondary part are formed between the teeth with recesses, the couplingteeth of the abutment fitting in the recesses of the secondary part andthe coupling teeth of the secondary part fitting in the recesses of theabutment, the teeth and recesses being formed with axially aligned blindbores, the spring means including respective compression springs in theaxially aligned blind bores.
 36. The vehicular arm rest defined in claim24 wherein the spring means includes a single compression springsurrounding the axis and bearing axially on the abutment and on thesecondary part.
 37. The vehicular arm rest defined in claim 24, furthercomprising overload-protecting means connected to the abutment forpermitting same to pivot on the axis with the secondary part when thearm-rest body is pressed toward the lowered position with a forceexceeding a predetermined limit.
 38. The vehicular arm rest defined inclaim 37 wherein the overload-protecting means includes a pusherrotationally fixed and axially shiftable on the axle, the abutment lyingbetween the pusher and the secondary part; coupling projections on thepusher and on the abutment extending toward each other and havingmutually engaging faces lying in planes extending at an acute angle tothe axis; and a spring pressing the pusher axially toward the abutment,the mutually engaging faces being angled and the spring having a forcesuch that, when the arm-rest body is pressed toward the lowered positionwith a force exceeding a predetermined limit, the mutually engagingfaces cam the pusher axially away from the abutment and permit limitedrotation of the abutment and secondary part on the axle.
 39. Thevehicular arm rest defined in claim 38 wherein the axle has a nonroundportion and the pusher has complementarily nonround bore fitted over thenonround portion.
 40. The vehicular arm rest defined in claim 38 whereinthe spring is a pack of spring washers.
 41. The vehicular arm restdefined in claim 38, further comprising a shield tube surrounding thepusher, the abutment, the secondary part, the primary part, and thespring.
 42. The vehicular arm rest defined in claim 41 wherein thearm-rest body includes a pair of arms extending radially from the axle,one of the arms being fixed to the primary part, the shield tube havingformations coupling both of the arms rotationally together.
 43. Thevehicular arm rest defined in claim 24 wherein the axle is splined alongits entire length, the pusher being splined to the axle, the abutment,secondary part, and primary part having smooth bores through which theaxle passes.